种植密度对松嫩平原西部白燕7号生产性能及光合特性的影响

Effect of planting density on production performance and photosynthetic characteristics of Avena sativa‘Baiyan No.7’in Western Songnen Plain

为了探明松嫩平原西部地区白燕7号(Avena sativa‘Baiyan No.7’)高产栽培适宜的种植密度,为松嫩平原西部地区饲用燕麦高产栽培提供理论依据。本研究设置300万(D1)、450万(D2)、600万(D3)、750万(D4)、900万(D5)和1050万(D6)株·hm–2共6个密度水平,分析种植密度对白燕7号生产性能及光合特性的影响。结果表明:1)随着种植密度的增加,白燕7号物候期提前,生育期缩短,生育后期的株高和茎粗显著降低(P<0.05),各生育时期的分蘖数显著降低(P<0.05)。2)种植密度对燕麦叶面积指数影响显著(P<0.05),随着密度的增加,燕麦叶面积指数从分蘖期至开花期呈升高的趋势,开花期至乳熟期呈先升高后降低的趋势。3)种植密度对各生育阶段光合势及总光合势均有显著影响(P<0.05),随密度的增加,光合势在孕穗期前呈升高的趋势,孕穗期后呈先升高后降低的趋势,总光合势呈先升高后降低的变化趋势。4)在开花期,燕麦旗叶光合性能随密度的增加而显著降低(P<0.05)。5)种植密度对各生育时期燕麦鲜草产量及干草产量均有显著影响(P<0.05),在大多数取样期,二者产量随密度增加呈先升高后下降的变化趋势,均在D5处理产量达到最高;在不同的生育时期,鲜草产量和干草产量均以乳熟期最高。综上,松嫩平原西部地区,白燕7号适宜种植密度为900万株·hm–2,且以乳熟期收获最佳。

A theoretical basis was provided to determine the suitable planting density for high yield cultivation of Avena sativa‘Baiyan No.7’in the Western Songnen Plain.Baiyan No.7 was chosen as the material to explore the effects of six density levels(D1:3 million plant·ha–1,D2:4.5 million plant·ha–1,D3:6 million plant·ha–1,D4:7.5 million plant·ha–1,D5:9 million plant·ha–1,and D6:10.5 million plant·ha–1)on production performance and photosynthetic characteristics.The results showed that with the increase in planting density,the phenological characteristics of Baiyan No.7 were enhanced,and the growth duration was shortened.The plant height and stem diameter of latter stages decreased significantly with the increase in planting density(P<0.05).The tiller number of each growth stage decreased significantly with the increase in planting density(P<0.05).The effect of planting density on oat leaf area index(LAI)was significant(P<0.05),and with increasing density,the LAI of oat increased from the tillering period to the anthesis period.The change from the anthesis period to the milk-ripening period first showed an increasing trend and then decreased.Planting density had a significant effect on photosynthetic potential at each growth stage and total photosynthetic potential(P<0.05).With increasing density,the photosynthetic potential first increased before the booting period,and then decreased after the booting period,and the total photosynthetic potential first increased and then decreased.During the anthesis period,the photosynthetic performance of flag leaves decreased significantly with increasing density(P<0.05).The planting density had a significant effect on the fresh yield and hay at each growth stage(P<0.05).In most sampling periods,the yields of both fresh oat and hay showed a tendency to first increase and then decrease with the increase in planting density,and reached the highest yield in the D5 treatment.In the different growth periods,the yield of fresh oat and hay was the highest at the milk-ripening period.In this study area,the suitable planting density of Avena sativa‘Baiyan No.7’was 9 million plant·ha–1,and the best harvest was at the milk-ripening period.