Microclimate modification using eco-friendly nets and floating row covers improves tomato (Lycopersicon esculentum) yield and quality for small holder farmers in East Africa

Tomato (Lycopersicon esculentum) is one of the important vegetables in supplying vitamins, min- erals and fiber to human diets worldwide. Its successful production in the tropics is, however, constrained by environmental variations espe- cially under open field conditions. Two trials were conducted at the Horticulture Research and Teaching Field, Egerton University, Kenya to evaluate the effects of agricultural nets (ag- ronets) herein called eco-friendly nets (EFNs) and floating row covers (FRCs) on microclimate modification, yield, and quality of tomato. A ran- domized complete block design with five repli- cations was used. Tomato plants were grown under fine mesh EFN (0.4-mm pore diameter) cover, large mesh EFN (0.9-mm pore diameter) cover or FRC. The EFN and FRC were main- tained either permanently closed or opened thrice a week from 9 am to 3 pm. Two open con- trol treatments were used: unsprayed (untreated control) or sprayed with chemicals (treated con- trol). The use of EFN or FRC modified the micro- climate with higher temperatures, lower diurnal temperature ranges, and higher volumetric wa- ter content recorded compared with the controls. On the other hand, light quantity and photo- synthetic active radiation were reduced by the use of EFN and FRC compared with the controls. The use of FRC and EFN resulted in more fruit and higher percent in marketable yield com- pared with open field production. Fruit quality at harvest was also significantly improved by the use of EFN and FRC. Fruits with higher total soluble solids (TSS), lower titratable acidity (TA), and higher sugar acid ratio were obtained in EFN and FRC treatments compared with the controls. Fruits harvested from EFN and FRC were also firmer compared with control fruits. These find- ings demonstrate the potential of EFN and FRC in modifying microclimate conditions and im- proving yields and quality of tomato under tropi- cal field conditions. (Résumé d'auteur)