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Sustainable soil nutrient management has been a current focus on different crop cultivation including cashew (Anacardium occidentale L.). Scarce availability of manure and high cost of inorganic fertilizers, triggered evaluation of cashew apple on soil fertility and performance of cashew. Cashew seeds were sown into soiled polythene bags incorporated with fresh, decayed, and fermented juicy of cashew apple at 0.25, 0.5, and 1.0 Kg/Kg Soil with 0.005 KgDAP and untreated as controls in screenhouse at TARI-Naliendele from 2019 to 2022. Findings revealed that fermented juicy and decayed apple at 0.25 Kg/Kg soil influenced 60–70% seed germination analogous with diammonium phosphate (DAP) and untreated (80–90%). About 1.0 Kg/Kg soil of decayed and fermented juicy exhibited higher plant height (70 cm), wider canopy spread (36.4 cm), and huge stem girth (2.6 cm) compared to others. Also, decayed apple had high number of branches and medium tap root with numerous lateral roots. High ground cover area (1011.5 cm2), leaf area (LA) (123.5 cm2), and canopy to girth ratio (14.5) were displayed with decayed and fermented juicy at 1.0 Kg/Kg Soil. On biomass yield, decayed and juicy had succulent fresh weight and high dry weight outperforming other treatments. Furthermore, decayed and fermented juicy exhibited high available nitrogen, phosphorus and potassium at 1.0 Kg/Kg Soil after 196 d of application. Fresh apple at all rates showed high soil moisture content and temperature. Therefore, this new research suggests the application of decayed cashew apple at 1.0 Kg/Kg soil as organo-fertilizers for replenishing soil nutrient and improving growth and development of cashew. [ABSTRACT FROM AUTHOR]

Cashew (Anacardium occidentale Linn.) is an important cash crop in Zambia. However, the cashew production is about 3–20 kgs/tree and the quality of the nuts is extremely poor due to the use of unimproved cashew genotypes. There are variations in cashew trees grown in farmers' fields because cashew is highly cross pollinated. As a short-term measure, farmers are currently planting cashew polyclonal seeds imported from Tanzania. Nevertheless, there are numerous cashew germplasm that were introduced to Zambia since 1940s. These cashew trees have adapted to the local environment and a small proportion of them are high yielding with good nut quality. Researchers need to identify these genotypes in farmers' fields and collect them as mother trees to initiate a cashew breeding programme. In Zambia, cashew research is still at its infancy hence the knowledge and skills are still low among the small-scale cashew farmers. Though cashew improvement programmes are being developed in several countries, there is enormous knowledge and technologies that have been generated from some cashew producing countries which could be adopted and later adapted in Zambia to revamp the whole cashew value chain. The approaches to accelerate cashew improvement in Zambia include; evaluation of germplasm for genetic diversity, conservation of germplasm, introduction of new alleles, selection of elite materials, vegetative propagation techniques, hybridization and marker assisted selection. This paper reviews the various knowledge, technologies and approaches that have been developed over time for cashew improvement and discusses their implication to the Zambia cashew industry. • Cashew is an important cash crop in Zambia. • Its yields are very low due to use of unimproved genotypes. • Since 1940s, many cashew germplasm varieties have been brought to Zambia. • However, cashew growers have limited knowledge and expertise in cashew genotypes. • Thus, germplasm diversity evaluation is vital to speed up cashew improvement. [ABSTRACT FROM AUTHOR]

Cashew (Anacardium occidentale L.) which is an important cash crop in Tanzania, is susceptible to various abiotic and biotic stresses. Cashew leaf and nut blight disease caused by Cryptosporiopsis spp. is a devastating disease of cashew crop resulting in a significant reduction of nut production. We conducted a study to assess the association between weather variables, particularly rainfall and temperature, on cashew leaf and nut blight disease (CLNBD) outbreaks and establish a minimum wetness duration period for initiation and development of the disease. Poisson regression analysis indicated a significant association between rainfall and temperature with CLNBD incidence (df = 3, Chi Pr < 0.001). Rainfall was positively associated with CLNBD and a unit increase of 1 mm in rainfall caused a 2 percent increase in the percentage of disease incidence (e = + 0.01995, p < 0.011). However, temperature was negatively associated with disease incidence and a unit increase of 1 °C in temperature caused a 21.56% decline in disease incidence (e = –0.2428, p < 0.001). Blight incidence was significantly higher (p < 0.001) during the rainy season (range: 11.7 to 36.6%) compared to the dry season (1.4 to 11.5%). Cashew trees in Mtwara District recorded higher blight disease incidence as compared to the rest of the studied areas. This study also established that symptoms for blight disease on cashew leaves appear 8 h post exposure to continuous wet periods. Thus, it appears that for the blight pathogen to initiate and complete its infection processes, a continuous wet period of at least 8 h is required. Findings from this study, particularly the association of rainfall and temperature on disease epidemics, can be used as tools for forewarning incidences of CLNBD. This would help timely initiation of appropriate management strategies. [ABSTRACT FROM AUTHOR]

Epidemic of Cashew Fusarium wilt disease (CFWD) has been a continuous focal challenge in the cashew farming, in Tanzania. Limited to edaphic conditions as a major factor in its epidemic, the current study aimed to assess the habitat-disease relationship. Purposive surveys involving assessment of disease prevalence and habitat compositions were conducted across four landscapes of southeastern zone from 2019 to 2023. Findings revealed a widespread of CFWD across diversified landscapes possessing varying habitat characteristics, mainly cultivated land with mature cashew, brownish sand loamy soils, grassland or shrub vegetation, seasonal river streamlines and natural water wells. The highest disease incidence and severity were noted at Nachingwea/Masasi plain (99.28:88.34%) followed by Liwale inland plain (98.64:89.3%), Coastal zone (72.72:59.83%) and Tunduru dissected plain (62.13:54.54%). The habitat characteristics were strongly similar within the landscape (0.86-Jaccard index) except between villages of the coastal zone (0.71-Jaccard index). Across landscapes, Nachingwea/Masasi plains and the Coastal zone were strongly similar to Tunduru dissected plain (0.63-1.0-Jaccard index), but strongly dissimilar with the Liwale inland plain (0.67-0.70- Jaccard distance). Furthermore, the presence of greater than 0.5 suitability indices across landscapes were revealed, with Liwale inland plain having strongest suitability index of 0.743 followed by Coastal zone (0.681), Tunduru dissected plain (0.617) and Nachingwea/Masasi plain. Significantly, the habitats had an increase of 0.1 suitability index, and positively correlated with disease prevalence by triggering disease incidence of 13.9% and severity of 31.4%. The study for the first time revealed the presence of an association between disease prevalence and landscape habitat characteristics of southeastern, Tanzania; paving the way to inclusive thinking of habitat as one of the drivers in the prevalence of fusarium wilt disease of cashews. Further research on the genetic coevolution of Fusarium oxysporum across landscapes to strengthen disease risk management in the cashew industry is recommended., (© 2024. The Author(s).)

Management of Fusarium oxysporum causing cashew wilt disease is a current focus in cashew industry, in Tanzania. Limitations of practiced cultural and chemical management, triggered evaluation of Azadirachta indica and Lantana camara against F. oxysporum in this study. Fresh leaf crudes of botanicals were extracted, impregnated on PDA at three doses (0, 0.4 and 0.6 ml/20 ml of Medium) and then incubated for five days. The tested botanical extracts significantly inhibited growth of F. oxysporum after five days of incubation (p ≤ 0.05). Application of A. indica (0.6 ml) and L. camara (0.4 ml) inhibited growth of F. oxysporum by 43.2% and 35.8% compared to control (0%). Significant correlation, revealed increased performance of botanical extract with increase of its doses (p < 0.001). The findings provide the promising efficacy of A. indica and L. camara on management of F. oxysporum on cashew. Further studies on in-vivo and field efficacy of botanicals are required. [ABSTRACT FROM AUTHOR]

Weaver ants,Oecophylla spp., provide adequate protection to crops against insect pests when their populations are high and stable. A study was conducted in a cashew field in Tanzania from November 2012 to October 2014 to determine temporal abundance ofO. longinoda. We determined (i) the number of shoots withO. longinodain a tree (established fortnightly) monitored at four cardinal points of a tree, using 1 m2wooden quadrats, (ii) the percentage of branches with ant trails per tree per month and (iii) the number of visible ant nests within the tree canopy per month. Furthermore, we assessed the association of weather and phenology withO. longinodapopulations. More weaver ant populations were recorded during reproductive and vegetative phases of cashew. We recorded significant positive associations between rainfall and temperature with the number of shoots withO. longinoda(p< .001), as well as relative humidity with the number of nests (p< .001). The percentage of shoots withO. longinodawas significantly associated with cashew growth phases. Rainfall and temperature negatively affected the number of nests. Consideration of cashew phenology and weather parameters can greatly enhance successful weaver ant augmentation strategies. [ABSTRACT FROM PUBLISHER]

BACKGROUND Cashew, Anacardium occidentale, is an economically important cash crop for more than 300 000 rural households in Tanzania. Its production is, however, severely constrained by infestation by sap-sucking insects such as Helopeltis anacardii, H. schoutedeni and Pseudotheraptus wayi. The African weaver ant, Oecophylla longinoda, is an effective biocontrol agent of hemipteran pests in coconuts in Tanzania, but its efficacy in the control of Helopeltis spp. and P. wayi in Tanzanian cashew has not been investigated so far. The aim of this study was therefore to evaluate the efficacy of O. longinoda in the management of these insect pests in the cashew crop at different sites of the Coast region of Tanzania. RESULTS Colonisation levels of O. longinoda, expressed as weaver ant trails, varied from 57.1 to 60.6% and from 58.3 to 67.5% in 2010 and 2011 respectively. The mean number of leaf nests per tree varied from five to eight nests in 2010 and from five to nine nests in 2011. There was a negative correlation between numbers of nests and pest damage. Oecophylla longinoda-colonised cashew trees had the lowest shoot damage by Helopeltis spp. of 4.8 and 7.5% in 2010 and 2011, respectively, as opposed to uncolonised cashew trees with 36 and 30% in 2010 and 2011 respectively. Similarly, nut damage by P. wayi was lowest in O. longinoda-colonised trees, with only 2.4 and 6.2% in 2010 and 2011 as opposed to uncolonised trees with 26 and 21%. CONCLUSION Oecophylla longinoda is an effective biocontrol agent of the sap-sucking pests of cashew in the Coast region of Tanzania and should be considered as an important component of IPM. © 2012 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

Cashew (Anacardium occidentale L.) is the present leading currency earning crop in Tanzania, generating income to over 2.5 million farmers. Despite of its importance, cashew is threatened by a new serious destructive disease called Cashew Fusarium Wilt (CFWD), which is caused by Fusarium oxysporum. The impact of the disease has reduced income at both household and national levels. The current study was conducted to characterize CFWD and investigate chemical management options for the disease. The study was conducted during the rainy and off-rainy season(s) at Tuungane-Liwale and Kitangari-Newala in Lindi and Mtwara regions respectively. Disease characterization involved field observation of the infected cashew trees, laboratory isolation and characterization of the causative agent. Chemical management involved application of azoxystrobin, carbendazim and thiophanate methyl each at a concentration of 5, 10 and 15 g of formulated product/L. Laboratory findings revealed that the causative agent of the cashew wilting symptoms is Fusarium oxysporum characterized by whitish mycelia growth, chlamydospores, macroconidia and microconidia. The tested chemical fungicides revealed significant effects on the suppression of Fusarium wilt disease and thus enhancing cashew recovery after 120 days of application. Azoxystrobin and carbendazim reduced severity and enhanced recovery. Application of azoxystrobin (15 g/L) promoted 65.2 percent recovery of cashew from 50.0 percent of disease severity and 10 g/L of carbendazim enhanced 49.4 percent of cashew recovery from 50.0 percent severity. Thiophanate methyl exhibited significant effect (P ≤ 0.05) on reducing the severity of the disease and enhancing cashew recovery whereby 15 g/L of thiophanate methyl enhanced 21.6 percent recovery from 45.0 percent severity. These findings advocate the administration of these chemicals, especially carbendazim and azoxystrobin in proper concentration for timely disease management in the affected areas. Studies to establish the effect of the applied chemicals to other biota for betterment and continued applications to combat the disease are underway. • Symptomology study of the cashew Fusarium wilt disease revealed yellow, brown leaf syndromes and stem gummosis. • Morphologically Fusarium oxysporum possessed whitish to brow/red brown pigmentation of fungal mycelia. • Microscopically, chlamydospore, macroconidia and microconidia were revealed. • Carbendazim, azoxystrobin and thiophanate methyl manage cashew Fusarium wilt disease in Tanzania. [ABSTRACT FROM AUTHOR]