摘要
Biostimulants are shown to increase crop production.This study was conducted to investigate the effects of individual biostimulants on tomato('Phoenix')growth and yield.Five biostimulants:CP_(1),CP_(2),BS,CP_(2)+BS,Competitor,and Water(control)were foliar applied at three different stages:pre-blooming,fruit setting,and color changing.The concentration of calcium(Ca),potassium(K),magnesium(Mg),and phosphorus(P)in leaves and roots were also determined.The results showed that plants treated with biostimulants had greater concentrations of Ca,K,Mg,and P compared to those treated with water only.Competitor and CP_(2)+BS significantly increased yield,plant height,and stem diameter by 76%and 41%,42%and 34%,and 29%and 24%.Likewise,leaf greenness,net photosynthetic rate(Pn),relative water content(RWC),nitrate level in petiole sap,and fruit quality(citric acid,malic acid,tartaric acid,soluble solid concentration,and fruit firmness)were also improved by Competitor.In addition,enzymatic activities of nitrate reductase(NR)and nitrite reductase(NiR)were significantly increased by biostimulants compared to the control.Statistically,Competitor and CP_(2)+BS showed the greatest augmentation in plant height,stem diameter,leaf greenness,PN,RWC,nitrate level in petiole sap,and fruit yield and quality.Similarly,Competitor-treated plants also increased NR,NiR,leaf Ca,leaf K,leaf Mg,and leaf P by 34%,70%,22%,26%,27%,and 45%,respectively.Based on the findings of this study,application of Competitor or CP2+BS showed promising results and may be used as a BMP tool for tomato production in Florida.
