Effects Of Different Humic Acids On Physiological Metabolism Of Summer Squash

Summer squash has become one of the main commodity vegetables in China,which is second only to the total yield of cucumber.In the process of cultivation,the disadvantages of traditional water and fertilizer management are gradually exposed,the occurrence of melon and disease is serious,the quality is poor,the yield is low,and the economic benefit is poor.It is the main problem that the cultivation of summer squash is facing to improve the yield and quality of summer squash.Humic acid can increase nutrient utilization,improve soil capacity,enhance crop resistance and reduce ecological environment pollution,so as to improve the growth conditions,increase plant yield and improve quality.The effects of FA,HA and BFA on the growth,physiological characteristics,yield and quality of the two cultivars were studied by barrel culture,using the heat-resistant variety ’Chun Fei Cui’ and ’Jing Hu’(Cucurbita pepo L.)as experimental materials:1.FA,HA and BFA treatment promoted the morphological indexes of ’Chun Fei Cui’ and "inghu summer squash.From 15 days to 60 days after planting,plant height,stem diameter and leaf area increased with time.The plant height of ’Chun Fei Cui’ and ’Jing Hu’ summer squash,FA and BFA is better than HA.In terms of stem diameter,the growth of ’Chun Fei Cui’ was the largest under BFA,while the stem diameter of ’Jing Hu’ cucurbit showed the trend of BFA >HA > FA;’Chun Fei Cui’ summer squash had better effect on its leaf area with HA.In the ’Jing Hu’ summer squash,FA and HA were significantly increased in the early stage of planting,but 45 days to 60 days after planting.The effect of BFA on the leaf area of ’Jing Hu’summer squash is more prominent.2.The N,P,K,CA,Mg and Zn elements of ’Chun Fei Cui’ and ’Jing Hu’ summer squash were significantly higher than CK under FA,HA and BFA treatment.Under BFA treatment,N,P,CA,Mg and Zn of ’Chun Fei Cui’ were 52.67% and 69.73%,46.58%,60.40% and 19.80% respectively.K element showed that HA had better absorption effect,increased by 120.87% compared with the control.The N,P,K,CA,Mg and Zn elements of BFA were 31.18%,67.26% and 92.55%,18.63%,63.2% higher than the control 5% and21.88% of the three humic acids had the best effect.3.Under FA,HA and BFA treatment,nitrate reductase(NR),glutamine synthetase(GS),glutamate dehydrogenase(GDH),glutamic acid synthetase(GOGAT),sucrose phosphate synthetase(SPS)and sucrose synthetase(SS)were significantly improved under BFA treatment.The best promotion effect was BFA treatment,and the ’Chun Fei Cui’ was the west of ’Chun Fei Cui’ Compared with the control,the NR activity,GS activity,GDH activity and GOGAT activity of the ’Jing Hu’ summer squash were increased by28.25%,64.01%,49.41% and 89.78% respectively,while the SPS activity and SS activity were 59.68% and34.93% higher than CK2 when the HA treatment was the largest.4.FA,HA and BFA treatment significantly promoted chlorophyll content,photosynthesis and fluorescence parameters of ’Chun Fei Cui’ and ’Jing Hu’ summer squash on 15,30,45 and 60 days after planting.The content of chlorophyll a,chlorophyll b and total chlorophyll in each period showed that A3 and B3 under biochemical humic acid treatment increased significantly.The net photosynthetic rate(Tr),transpiration rate(Pn),stomatal conductance(GS),intercellular CO2 concentration and maximum photochemical efficiency(Fv/Fm),photochemical efficiency(Fv’/Fm’)under light,actual photochemical efficiency(ΦPSⅡ),electron transfer rate(ETR),photochemical quenching coefficient(q P)were all improved compared with the control,and the initial fluorescence(fo),initial photochemical efficiency(q P)were improved.The fluorescence(fo′),non photochemical quenching(NPQ)and non photochemical quenching coefficient(q N)were decreased compared with the control,and the BFA treatment increased and decreased the largest.5.FA,HA and BFA treatment can improve the yield and quality of ’Chun Fei Cui’ and ’Jing Hu’ summer squash to some extent.The results showed that the weight of fruit per plant and yield per plant increased,and the increment of ’Chun Fei Cui’ was the most in BFA.The increase of fruit weight per plant,the content of soluble sugar,soluble protein,VC and organic acid of the ’Chun Fei Cui’ was the most obvious,which was 7.81%,29.26,57.84%,56.77%,66.16% and 50.22% higher than the control,respectively.BFA was higher than the other two The results showed that the increase of BFA was the highest in the weight of fruit and yield per plant,soluble sugar content,soluble protein content,VC content and organic acid content of ’Jing Hu’ zucchina,which was 6.00%,25.81%,40.00%,72.38%,121.62% and 84.00%higher than that of the control group,and 21.55% lower than that of the control.In conclusion,the results showed that the biochemical humic acid had better effects on the morphological indexes,nutrient elements,carbon and nitrogen metabolism enzyme activity,photosynthesis,yield and quality of summer squash.Three kinds of humic acids increased the yield and quality of Jinghu more.