USE OF BIO-NANOCOMPOSITES IN ENHANCING BACTERIAL WILT PLANT RESISTANCE, TOMATO PRODUCTION AND WATER CONSERVATION IN GREENHOUSE FARMING

Abstract

This study was conducted to examine the effects of bio-nanocomposites in increasing bacterial wilt resistance, growth and development and water conservation in tomato production in a greenhouse. The experiment was conducted using completely randomized design (CRD) with 19 treatments and 3 replications. The effect on resistance elicitation in different tomato varieties was analysed using polymerase chain reactions (PCR) by determining the presence and concentration of chitinase and glucanase. Enhanced resistance was determined using bioassays on reported wilt incidences in tomato seeds and seedlings treated with bio-nanocomposite and challenged with the Ralstonia solanacearum. Effect of bio-nanocomposites in tomato plants yield and shelf life was determined in form of the obtained yield and longevity of stored tomato fruits after harvesting. Water conservation in propagated seedlings and tomato plants rhizosphere growing in the greenhouse was determined using a digital potential meter based on percent moisture loss after irrigation. Enhancement of the two genes (chitinases and glucanases) in the DNA tests coupled with reduced wilting of the tomato crops in bio-nanocomposites treatments indicated induced resistance. In contrast, tomato seedlings grown in the control, had reduced growth and were significantly (P<0.05) infected by the wilting disease. There was significant difference in yield and shelf life between the treatments and controls (P<0.05). In addition, the nanocomposite significantly resulted in enhanced water conservation (P<0.05).  The BCAs and chitosan silica nanocomposites are able to increase physiological, biochemical and soil microbial activities enhancing tomato production and resource utilization efficiency. The study therefore, heralds the era of using bionanocomposites in induction of host plant resistance, improved tomato productivity, increased tomato fruit shelf life and water conservation due to the resultant synergies of the constituent elements.

 Key words: Chitosan immobilized silica nanocomposites (CISNC); Biological antagonists; chitinases; glucanases; yield; post harvest losses.