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Experimental research has been focusing on developing new substrates for growing shiitake mushrooms as alternatives to the standard oak sawdust substrate. The selection of appropriate lignocellulosic materials is based on their availability in the production area and their compatibility with the requirements of the mushroom species being cultivated. In comparison to oak sawdust substrate (OS) as the control, this study evaluated the potential of oak acorns (OA), olive pruning (OLPR), and vineyard pruning (VIP), and various combinations: OA-OLPR:1-1, OA-VIP:1-1, OS-OLPR:1-1, and OS-VIP:1-1, prepared on a dry weight basis. In comparison to OS, complete mycelial development was hastened in OA, OA-VIP: 1-1, and OS-VIP:1-1 by 9.5, 7.9, and 4.2 days and delayed in OLPR and OS-OLPR:1-1 by 11.3 and 7.0 days, respectively. Also, harvest was earlier in OA, OA-VIP:1-1, and OS-VIP:1-1 by 9.3, 6.7, and 3.3 days, respectively, while it was significantly delayed in OLPR, VIP, and OS-OLPR:1-1 by 12.3, 3.7, and 8.0 days, respectively. While the total biological yield was significantly reduced in OLPR, OS-OLPR:1-1, VIP, and OS-VIP:1-1, it was comparable to OS in OA, OA-OLPR:1-1, and OA-VIP:1-1 (597.0, 552.0, 532.2, and 556.2 g/kg, respectively). Production was consistently high over two consecutive flushes in OS, OA, and OA-VIP: 1-1. Total biological yields were higher in OA-OLPR: 1-1 than OS-OLPR:1-1 and in OA-VIP:1-1 than OS-VIP:1-1. OA increased mushroom number and firmness, VIP and OLPR increased mushroom weight, and OA-VIP:1-1 increased pileus thickness. Mushrooms’ protein and fiber contents were higher than OS in all substrates and the highest in OA-OLPR:1-1 (8.7 %) and OLPR (2.8 %), respectively. Conclusively, the substrates OA, OA-VIP: 1-1, and OA-OLPR:1–1 may alternate oak sawdust; however, the first two substrates have an advantage over the third due to earlier harvests. Also, it is more favorable to use VIP and OLPR in combination with OA than to use them alone.

In the last decade, annona crop was introduced to Lebanon. This experiment was conducted to enhance the adaptation of annona to local conditions. Three scion/rootstock combinations were obtained from self– and cross– cleft grafting of Annona squamosa (Sq) and Annona cherimola (Ch), planted in calcareous “white soil” and clay–loamy “red soil”, and fertilized or not by iron (Fe) through fertigation. In the third year, the treatment red soil–iron fertilization–Sq/Ch had significantly highest plant height, trunk diameter, leaf number, number of primary roots, fruit number and yield. In the third year, despite iron fertilization, plants of the three graft combinations cultivated in red soil had higher flower number, fruit number, individual fruits weight and yield, than those planted in white soil. In the same year, iron fertilization in white soil had only affected total dry mass, leaf mass fraction and leaf iron content. However, iron fertilization of Sq/Ch planted in red soil has improved leaf number, primary root number, primary root length, leaf chlorophyll index, and leaf iron content compared to non–fertilized plants. Conclusively, iron fertilization in red soil could be a useful method improving the performance and yielding capacity of annona crop mainly in Sq/Ch combination.

Recently, the introduction of tropical crops in Lebanon represented a challenge for farmers and researchers. Constraints to the adaptation of such crops, to climatic and soil conditions were found. In this study, an orchard of Annona trees (Sq/Ch combination) was irrigated by minisprinkler system and drip system, and compared to a control (not irrigated) over two consecutive years (year 4 and year 5 of the project). Compared to the control, plant height and leaf number were improved the most in year 5 by drip irrigation. Leaf water potential that peaked in the summer season in control plants (-1.8 MPa) was the lowest in plants irrigated by drip system (-1.3 MPa). No significant difference was observed between treatments in the number of lateral shoots. TDM of plant parts was improved by drip irrigation in both experimental years by 81 g (year 4) and by 258 g (year 5). LMF was significantly enhanced in year 5 by the mini-sprinkler system. RMF was the highest in trees irrigated by drip irrigation (0.265 g/g) and the lowest in the control (0.227 g/g). SMF was the highest in control trees in both experimental years. It seems that drip system presented an optimal method for the irrigation of annona.

Various abiotic stresses affect growth and development of plants and one of them that causes severely decreasing the horticultural and crop yields is the heat stress worldwide. In this paper, the effects of heat (more than 30-35 °C in different species) stress on the horticultural plants and crops, and its effects on inducing other stresses, including osmotic and oxidative stresses are discussed. Plants show the molecular and biochemical responses after receiving environmental signals such as high temperatures and tolerate undesirable conditions.

Various abiotic stresses affect growth and development of plants and two important cues that cause to sever decrease the horticultural and crops yield are the heat and chilling stresses worldwide. Plants have various mechanisms to tolerate or avoid the stresses; one of these mechanisms is the biosynthesis of organic solutes. In this paper, effects of chilling (0-15 °C) stress on the horticultural (ornamental and vegetable) plants and crops are discussed. You will see that plants how to tolerate the stress by organic solutes. The most important organic molecules to regulate water relations in plants are introduced. The organic solutes that also are called osmo-protectants include soluble carbohydrates, amino acids and nitrogen compounds.