宁夏苹果花期霜冻敏感性指标研究

苹果花期霜冻指标是果园霜冻预报预警、防御的基础,本文运用人工模拟霜箱,以富士、嘎啦和乔纳金苹果为试验对象,设置过冷却模拟试验设5个温度梯度和4个持续时间共计20个试验处理,模拟研究了苹果花期霜冻敏感性指标。结果表明:苹果花苞期花瓣、盛花期花瓣和子房以及幼果期的幼果平均过冷却点在-3.51℃~-3.27℃,结冰点变化范围在-2.94℃~-2.65℃。苹果花期低温敏感范围在-2.5℃~-3.5℃之间,不同花器官、不同品种、不同低温持续时间和不同发育阶段之间有所差异,其中,在苹果花的花瓣、子房、雄蕊和雌蕊等不同花器官中,花瓣最不耐冻,子房和雌、雄蕊随温度降低变异较大;不同类型花耐受冻顺序为花苞半开花全开花;-2.5℃~-3.0℃温度处理下,致死率随持续时间增加明显,温度高于或低于这个范围,持续时间对致死率影响不大;3个苹果品种中,富士最不耐冻,其次是乔纳金和嘎啦。     

乔砧富士苹果改良高干开心形树冠郁闭的评判参数

【目的】研究富士苹果改良高干开心形树冠郁闭的评判参数,为苹果郁闭园改造提供理论依据。【方法】以20年生改良高干开心形富士苹果为材料,以树干为中心,将树冠分成不同层次、方位的50cm×50cm×50cm的立方体,在生长期测量树冠不同层次、部位的相对光照强度、不同枝(梢)类型的数量和比例、果实产量和品质分布。【结果】改良高干开心形树冠的相对光照强度呈伞形,并有明显的分布规律,垂直方向从下到上逐渐增大,水平方向外围中部内膛;树冠2.5m高度以下层次的相对光照强度均小于31.48%;6月份叶幕形成阶段,30%的相对光照强度占树冠体积的比例为47.62%,以后各生长阶段均50%;果实主要集中在1.5—2.0m部位,单位面积产量6.32×104kg·hm-2;枝(梢)主要集中在树冠2.5m高度以下,占总枝(梢)量的82.92%,树冠外围、中部和内膛枝(梢)比例分别为53.08%、36.92%、10.00%;整体长、中、短枝(梢)分别7.97%、53.63%、38.41%,每公顷枝(梢)总量为121万条。【结论】富士苹果改良高干开心形树冠内小于30%相对光照强度占树冠总体积的比例达到47.62%、生长季枝(梢)总量达到121万条/hm2和树冠内膛枝(梢)比例小于10%是乔砧富士苹果改良高干开心形树冠郁闭的3个判断指标,也是树体结构开始改造或间伐的时期。     

2000年以来中国苹果产业发展趋势分析

对2000年以来我国苹果生产、消费和贸易情况进行分析发现,我国苹果生产区域布局较为稳定,生产高度集中于苹果生产优势区域。苹果生产效率大幅提升,不断满足城乡居民对苹果的消费需求,城乡差距不断缩小,苹果产品贸易顺差进一步扩大。但苹果生产成本利润率显著下降,消费者对苹果品质及营养也提出了更高的要求,苹果生产面临成本、质量等方面的挑战。与此同时,苹果生产中技术服务、农业保险等社会化服务也有了初步发展,未来苹果生产将进一步向高效、优质、社会化发展。     

套袋对两个苹果品种果实香气成分的影响

为了解套袋对苹果品种新富1号(Malus domestica Borkh.cv.Xinfu No.1)、长富2号(M.domestica cv.Fuji Nagafu No.2)果实香气成分的影响。利用顶空固相微萃取和气相色谱-质谱联用技术,分别测定了套袋后2个苹果品种的香气成分。结果表明,2个富士苹果品种果实香气成分均以酯类和醇类化合物为主。在酯类化合物相对含量上,未套袋果实套袋果实;在醇类化合物相对含量上,套袋果实未套袋果实。新富1号果实香气成分以乙酸乙酯、乙酸丁酯、2-甲基乙酸丁酯、丁酸乙酯、乙酸己酯为主,长富2号果实香气成分以2-甲基乙酸丁酯、乙酸己酯、正戊酸己酯、2-甲基-1-丁醇、丁酸乙酯、丁酸丙酯、乙酸丁酯、2-甲基丁酸乙酯、丙酸乙酯为主,2个苹果品种的果实主要香气成分基本一致。不过套袋果实乙酸酯型香气成分相对含量均低于未套袋果实。     

苹果多酚抑菌效果的研究

观测苹果多酚对细菌、酵母菌、霉菌生长的影响以及对各种供试菌株在测试浓度范围内的最低抑菌浓度,以期为新型安全天然食品防腐剂的研究提供一定的依据。采用双层平板打孔法,研究了不同质量浓度(2、6、10g/L)苹果多酚,对6种细菌、3种酵母菌及3种霉菌的抑制作用,对筛选出来的供试菌株,采用0.3、0.4、0.5、0.6、0.7、0.8、1.0、2.0g/L8种不同浓度的苹果多酚进行测试浓度范围内最低抑菌浓度试验。结果表明:苹果多酚对黄杆菌SHL45、大肠杆菌、荧光假单胞菌SHL5、荧光假单胞菌SHL7、枯草芽孢杆菌、金黄色葡萄球菌6种供试菌株,在苹果多酚测试浓度范围内的最低抑制浓度分别为0.6、0.7、0.6、0.6、0.8、0.5g/L,对金黄色葡萄球菌等6种供试菌株有明显的抑制作用。     

甜百虫对红富士苹果疏除效应的研究

研究了敌百虫对“红富士”苹果疏除效应及落花落果动态。试验结果表明 :“红富士”苹果于盛花后 14d喷布 90 0mg·L-1的敌百虫 ,其疏除效应达到生产要求 ,可有效地提高单果重及翌年花芽量 ,减小大小年幅度 ,增加产量及提高果品质量     

甲壳素对连作平邑甜茶生长、光合及抗氧化酶的影响

以苹果连作土盆栽的平邑甜茶幼苗为试材,探讨了0、0.5、1.0和2.5 g·kg-1不同施入量的甲壳素对其光合速率、活性氧含量及抗氧化酶活性的影响。结果表明,1.0 g·kg-1的甲壳素处理能显著促进幼苗株高、地径,干样质量和根冠比的增加,根冠比为对照的1.51倍;明显提高了幼苗叶片光合色素含量、净光合速率和蒸腾速率,其中光合速率为对照的1.30倍;同时提高了幼苗叶片超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)和抗坏血酸过氧化物酶(APX)活性,分别为对照的1.10倍、1.85倍、1.77倍和1.43倍;减少了叶片丙二醛(MDA)、过氧化氢(H2O2)和超氧阴离子的积累,分别为对照的73%、62%和34%,降低了脯氨酸(Pro)和可溶性糖含量。当甲壳素施用量为2.5 g·kg-1时则显著抑制平邑甜茶幼苗生长,降低幼苗叶片光合速率和抗氧化酶活性,并使超氧阴离子和脯氨酸含量明显上升。因此,适宜用量的甲壳素能减轻苹果的连作障碍。     

Assessment of the socio-economic impacts associated with the arrival of apple snail (Pomacea canaliculata) in Mwea irrigation scheme,Kenya

Background

In Kenya, rice (Oryza sativa L.) is mainly produced under irrigation by small-scale farmers. Mwea irrigation scheme (MIS) in Kirinyaga County accounts for 80–88% of rice production. Here, rice is the main source of livelihood and a source of revenue generation for the county. However, a recently established invasive freshwater snail, Pomacea canaliculata (Lamarck) (family: Ampullariidae), a species of apple snail, presents a serious threat to rice production.

Results

Household surveys, focus group discussions and key informant interviews highlight apple snail as a serious problem in MIS. Households that observed at least a moderate level of infestation (>20% of cultivated area) experienced significant reductions in rice yield (~14%) and net rice income (~60%). Farmers reported increased use of chemical pesticides for management of apple snail. In addition, the cost of hired labor for physical removal of egg masses and snails is resulting in substantial negative effects on net income. Farmer age, area of land owned, responsibility for decision-making, receipt of extension advice, training, and membership of a farmer organization, were all statistically significant variables to explain farmers awareness of the need for area-wide apple snail management.

Conclusion

Strategies to limit the spread of apple snail are urgently needed. A Multi-Institutional Technical Team (MITT) has been established to spearhead management efforts and consolidate advice to farmers on how to manage apple snail. However, without action to mitigate spread, the consequences could be disastrous for rice production and food security in Kenya, and for other rice growing regions across Africa. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.     

利用苹果加工下脚料生产膳食纤维的研究

主要研究利用苹果加工后的下脚料生产膳食纤维的工艺流程、操作要点、产品质量标准及综合利用效益。     

Effects of arrangement of surge-rootirrigation emitters on growth,yield andwater use efficiency of apple trees

Six-year old apple trees were selected for field experiment. The objective of this study was to obtain the reasonable arrangement of surge-root irrigation emitters in apple orchards. There were three factors: the buried depth H( 25,40,55 cm),the horizontal distance L( 30,40,60 cm) between the emitters and the trunk of the experimental tree,and the number of the irrigation emitters N( 1,2,4). The effect of the arrangement of surge-root irrigation emitters on the growth,yield and irrigation water use efficiency( IWUE) of apple trees were studied in Northern Shaanxi where the irrigation quota takes 60%-75% of the field water capacity. The results showed that the arrangement of emitters for surge-root irrigation had a significant effect on apple tree yield and IWUE,especially,the yield and IWUE reached 28 388. 17 kg/hm2 and 16. 83 kg/m3 in treatment T3,respectively. At the same L and N levels( T1,T2,and T3),the yield and IWUE in treatment T3 were the highest,and the yields in treatments T1 and T2 were decreased by 26.22% and 31.48%,while IWUE is reduced by14.02% and 18.12% compared with T3,respectively. At the same H and N levels( T3,T4,and T5),the yield and IWUE of apple trees were decreased with increasing L level. Especially,when L was 30 cm( T3),the yield and IWUE were the highest. The same L and H levels( T3,T6,and T7) could promote the growth of apple trees when N was 2( T3). Compared with treatment T3,it was found that the increment of new shoots was decreased by 8.07%-18.71%,and the fruit diameter was decreased by 5.41%-9.11%. Therefore,two emitters should be arranged symmetrically on both sides of an apple tree,each was buried at a 40 cm depth and 30 cm away from the trunk of the tree to effectively improve the yield and IWUE of the apple tree in mountainous areas in Northern Shaanxi.