旺长期干旱胁迫对红麻生长发育、产量及效益的影响

为探讨干旱胁迫对红麻生长及产量的影响，寻找最佳节水灌溉临界值，以红麻品种杂红992为试验材料，通过盆栽控水法研究不同干旱胁迫强度和时长对红麻生长发育指标（叶片数、株高、茎粗和地上干物质量）、产量和经济效益的影响。结果表明，干旱胁迫显著降低了红麻生长量，减缓了生长速度，且降低幅度与胁迫强度和时间呈正相关。干旱胁迫后的红麻在复水后将会进行补偿性生长。与正常灌溉相比，短时（5d）的轻度（土壤含水量控制在60%～65%）或中度（土壤含水量控制在40%～45%）干旱胁迫不仅可以节水45%～73%，而且提高产量8%～14%，综合经济效益提高2445～3729元/hm2。但重度（土壤含水量控制在20%～25%）或长时间（>15d）干旱胁迫降低了补偿效应甚至产生伤害。因此，从红麻生产的高产、高效出发，确定土壤含水量占田间最大持水量的40%～45%作为红麻旺长期增产、增效的水分临界指标。

Effects of Drought Stress on Growth,Yield and Benefits of Kenaf in Vigorous Growing Period

In order to explore the effects of drought stress on kenaf growth and yield, and find the optimal critical value of water-saving irrigation, the effects of water stress on growth and yield of kenaf was studied in Zahong 992. The effects of different drought stress conditions on the growth indexes (leaf number, plant height, stem diameter and aboveground dry matter weight), yield and economic benefits of kenaf were studied by pot water control method. The results showed that drought stress significantly reduced the growth of kenaf and slowed down the growth rate of kenaf, and the increase of decreasing range was positively correlated with stress intensity and time. Kenaf after drought stress will undergo compensatory growth after rehydration. Compared to normal irrigation, short (five days) drought stress of mild (60%-65% soil moisture content) or moderate (40%- 45% soil moisture content) could save 45%-73% water. Moreover, the yield of kenaf can be increased by 8%-14%, and the comprehensive economic benefit could be increased by 2445-3729 yuan/ha. However, severe (20%-25% soil water content) or long-term (> 15 days) drought stress reduced the compensation effects and even caused injury. So, the soil water content accounting for 40%-45% of the maximum field water capacity was determined as the water critical index for the long-term increase of yield and efficiency.