陇东旱区梨园地面覆盖对树体生长和结果性状的影响

Effects of Mulching on the Growth Rhythm and Fruit Characters of Pear in Longdong Dryland Regions

为探明垄膜覆盖(T1)、覆草(T2)和免耕(T3)对陇东旱塬区梨(Pyrμs bretschneideri Rehd.)园树体生长和结果的影响,测定分析了不同覆盖条件下梨园土壤温湿度变化及叶片和果实特征。结果表明:梨树花期至幼果膨大期,不同土层温度均以T1最高,T2最低,新梢停止生长后,处理间差异减小,至落叶期趋于一致。梨树生长前期(4-6月),T3土壤含水量最小,7月以后T3最高。在梨树年生长周期中,T1土壤含水量变化最小,T3最大。T2叶片栅栏组织最发达,栅栏组织长度和厚度均显著高于T1和T3,T1栅栏组织厚度显著高于T3,处理间叶片海绵组织差异不显著。T2总叶绿素含量显著高于T3,但与T1差异不显著。覆盖显著提高了叶片钾含量;T2叶片钙、镁含量最低,而铁、硼含量最高;T1除铜含量最高外,锌、锰、铁、硼含量均最低;T3钙、镁、锌、锰含量最高。T1和T2分别比T3增产16.0%和10.2%。覆盖后果实维生素C含量显著降低,T1显著低于T2和T3。处理间果实硬度、可溶性固形物、可溶性糖、有机酸、水分含量差异均不显著。T1,T2和T3的糖酸比分别为22.7,22.8和22.0。

To ascertain the effects of ridge film mulching （T1） ,straw mulching （T2） and no-tillage （T3） on pear growth and fruiting, the changes of soil temperature and humidity, the leaf and fruit characteristics of pear were measured and analyzed in Longdong dryland regions. Results showed that treatment T1 had the highest soil temperature and T2 had the lowest one during the growth stage of fruit. The differences of soil temperature among treatments decreased after new shoots stop growing. Treatment T3 had the minimum soil moisture content at growth prophase （from April to June） and had the highest one after July. The soil moisture change of T1 during the annual growth cycle of pear tree was minimal, whereas that of T3 was maximal. The leaf stockade tissues of T2 were the most flourishing. The length and thickness of leaf pali- sade tissue of T2 were significantly higher than that of T1 and T3. The palisade tissue thickness of T1 was significantly higher than T3. The leaf spongy tissue had no significant difference among treatments. The total chlorophyll content of T2 was significantly higher than T3, but no significant difference compared with T1. Mulching significantly improve the potassium content of leaf. The leaf calcium and magnesium contents of T2 were minimal, whereas iron and boron contents were maximal. The copper content of T1 was the highest, whereas zinc, manganese, iron, boron contents were the lowest. The calcium, magnesi- um, zinc and manganese contents of T3 were the highest. T1 and T2 increased yield by 16.0% and 10.2% compared to T3. Mulching lessened the vitamin C contents of fruit. The fruit vitamin C contents of T1were significantly lower than T2 and T3. The fruit hardness, soluble solid contents, soluble sugar and or- ganic acid, moisture contents among treatments had no significant difference among treatments. The sug- ar-acid ratios of T1, T2 and T3 were 22.7, 22.8 and 22.0, respectively.