Search

Biochar made from crop residues has been shown to improve soil texture, soil porosity and soil structure. It can enhance fertilizer utilization, reduce leaching loses and hence improve nitrogen supply for plant growth. Utilization of biochar in preparation of potting substrates can enhance growth and yields of greenhouse tomato. A study was carried out to test the influence of rice husks biochar on substrate properties, growth and yield of greenhouse tomato. The experiment was carried as a factorial in completely randomized design with two factors: four biochar levels and two soil types, replicated three times. The biochar levels were volume ratios of 0 biochar: 1 soil (OBiochar), 0.25 biochar: 0.75 soil (0.25Biochar), 0.5 biochar: 0.5 soil (0.5Biochar) and 0.75 biochar: 0.25 soil (0.75Biochar). The two soil types used were the well drained deep red friable soil and imperfectly drained dark brown clay soil obtained from the University farm. Tomato Anna F1 was grown in four-liter plastic pots containing about 3 kg of soil-biochar mixture. Data were collected on the plant growth parameters of plant height, number of leaves per plant and plant dry weight upto the 8th - 9th week after transplanting, when fruit ripening began. The chlorophyll index of the leaves were measured using the SPAD meter. At harvesting, fresh weight and number of the fruits were determined. Incorporating biochar into potting substrate at 0.25-0.75 levels significantly increased evapotranspiration during early vegetative growth. This was indicative of biochar changing substrate properties mainly through significant reduction of bulk density and possibly increasing porosity. Biochar levels of 0.25-0.75 resulted in significant increases in vegetative growth and fruit yield of tomato. Adding biochar to the pot substrate increased tomato plant height, plant dry weight and fruit fresh weight by 21-34%, 50-64% and 49%-56%, respectively. The increase in vegetative growth and fruit yield at 0.25-0.75 biochar levels was attributed to the positive effect of biochar on substrate physical properties. Plant height and number of leaves per plant had a significant linear relationship whose slope, the rate of increase in plant height with increase in number of leaves was not influenced by biochar levels. Biochar enhanced growth without changing the ratio of plant height to number of leaves of tomato. It is concluded that incorporation of biochar made from rice husks at 0.25 level can enhance greenhouse production in both red and clay soils. Key words: Bulk density, Dry weight, Fresh fruit weight, Number of leaves, Plant height, INTRODUCTION Biochar is a by-product of pyrolysis involving the thermal decomposition (exothermic) of biomass in an oxygen limited environment. Conversion of local bio-waste into biochar and its utilization as a [...]

We examined a series of eight pea genotypes differing in three naturally occurring allelic mutations, i.e., af (afila), st (stipules reduced), and tl (tendril-less) and three species, five cultivars, and one interspecific hybrid of tomato differing in SP (SELFPRUNING) allele composition to determine whether different phenotypes ontogenetically express different biomass partitioning patterns compared to the isometric poatitioning pattern and an interspecilic 3/4 scaling 'rule'' governing annual growth with respect to body mass. The slopes and 'elevations' (i.e., a and log [beta], respectively) of log-log linear regression curves of bivariate plots of leaf. stem, and root dry mass and of annual growth vs. total body mass were used to assess pattern homogeneity. The annual growth of all pea and tomato phenotypes complied with the 3/4 growth rule. The biomass partitioning patterns of all tomato phenotypes were statistically indistinguishable from the isometric pattern as were those of the pea wild type and three singlemutant genotypes. However, significant departures from the isometric (and pea wild type) biomass allocation pattern were observed for three genotypes, all of which were homozygous for the af allele. These results open the door to explore the heritability and genetics underlying the allometry of biomass partitioning patterns and growth. Key words: af (afila); allometry; Fabaceae; Lycopersicon esculentum; Lycopersicon pennellii; Lycopersicon pbnpinellifolium; leaf morphology; Piston sativum; scaling relationships; Solanaceae.

Plant defense responses to wounding and herbivore attack are regulated by signal transduction pathways that operate both at the site of wounding and in undamaged distal leaves. Genetic analysis in tomato indicates that systemin and its precursor protein, prosystemin, are upstream components of a wound-induced, intercellular signaling pathway that involves both the biosynthesis and action of jasmonic acid (JA). To examine the role of JA in systemic signaling, reciprocal grafting experiments were used to analyze wound-induced expression of the proteinase inhibitor II gene in a JA biosynthetic mutant (spt-2) and a JA response mutant (jai-1). The results showed that spr-2 plants are defective in the production, but not recognition, of a graft-transmissible wound signal. Conversely, jai-1 plants are compromised in the recognition of this signal but not its production. It was also determined that a graft-transmissible signal produced in response to ectopic expression of prosystemin in rootstocks was recognized by spr-2 but not by jai-1 scions. Taken together, the results show that activation of the jasmonate biosynthetic pathway in response to wounding or (pro)systemin is required for the production of a long-distance signal whose recognition in distal leaves depends on jasmonate signaling. These findings suggest that JA, or a related compound derived from the octadecanoid pathway, may act as a transmissible wound signal. Lycopersicon esculentum | jasmonic acid | systemin | systemic signaling | induced resistance

An innovative technique of growing tomatoes is examined, focusing on its impact on agricultural yield. Topics include a discussion of sustainable versus conventional agricultural methods, the new technique of planting tomatoes, and the technique's possible economic impact on the vegetable industry.