作者: Martínez de la Parte, Einar ; Meijer, Harold J G ; García-Bastidas, Fernando ; Kema, Gert H J ; Pérez-Vicente, Luis ; Schnabel, Sabine ; Bermúdez-Caraballoso, Idalmis

Bananas are major agricultural commodities in Cuba. One of the main constraints of banana production worldwide is Fusarium wilt of banana. Recent outbreaks in Colombia, Perú, and Venezuela have raised widespread concern in Latin America due to the potential devastating impact on the sustainability of banana production, food security, and livelihoods of millions of people in the region. Here, we phenotyped 18 important Cuban banana and plantain varieties with two Fusarium strains—Tropical Race 4 (TR4) and Race 1—under greenhouse conditions. These varieties represent 72.8% of the national banana acreage in Cuba and are also widely distributed in Latin America and the Caribbean region. A broad range of disease responses from resistant to very susceptible was observed against Race 1. On the contrary, not a single banana variety was resistant to TR4. These results underscore that TR4 potentially threatens nearly 56% of the contemporary Cuban banana production area, which is planted with susceptible and very susceptible varieties, and call for a preemptive evaluation of new varieties obtained in the national breeding program and the strengthening of quarantine measures to prevent the introduction of TR4 into the country.

2023-02-08·Huan jing ke xue= Huanjing kexue

[Effects of Fertilization and Straw Mulching on Nitrogen and Phosphorus Loss in Chengdu Plain].

Article

作者: Zhai, Li-Mei ; Zhang, Qi ; Luo, Fu-Xiang ; Wang, Hong ; Yao, Li ; Liu, Hai-Tao ; Wang, Xie ; Yang, Xuan ; Lin, Chao-Wen

In recent years, the excessive application of nitrogen and phosphorus fertilizers has caused serious pollution and eutrophication, especially in paddy fields. Accordingly, a two-year (2018-2019) study was conducted at a rice paddy field under different fertilizer application rates and straw mulching in Chengdu Plain. N and P losses through the rainfall and surface runoff in the paddy field were measured under natural rainfall conditions. The results showed that nitrogen mainly existed in the form of ammonium nitrogen, and phosphorus mainly existed in the form of soluble phosphorus in the wet deposition. The wet deposition of nitrogen and phosphorus mainly occurred in June, July, and August. Surface runoff was positively correlated with rainfall, whereas surface runoff nitrogen concentration was inversely correlated with rainfall. The highest runoff losses of TN (4.75 kg·hm^-2 in 2018 and 2.68 kg·hm^-2 in 2019) were produced by TR3 practice and were 26.73% and 43.32% higher than that of the conventional practice. TN runoff loss was significantly decreased by reducing the rate of N fertilizer (P<0.05). Compared with that in the conventional practice TR1, TR4 reduced the N loss by 36.33% in 2018 and 26.74% in 2019, respectively. Optimized fertilizer TR2 and nitrogen reduction practice TR4 decreased P loss from surface runoff, and high intensity rainfall could reduce the content of granular phosphorus in surface runoff. The surface runoff occurring in July, August, and September contributed mostly to the total N loss, whereas the loss of total P mainly occurred before July. Consequently, the use of balanced fertilizer and decreased nitrogen fertilization amount might be effective strategies to attenuate non-point source pollution in the Chengdu Plain in the paddy fields.

2019-03-01·Translational Animal Science

Effects of zinc source and level on growth performance and carcass characteristics of finishing pigs1,2

Article

作者: Carpenter, Corey B ; Dritz, Steve S ; DeRouchey, Joel M ; Tokach, Mike D ; Woodworth, Jason C ; Cemin, Henrique S ; Usry, James L ; Goodband, Robert D

AbstractAn experiment was conducted to determine the effects of added Zn source and level on growth performance and carcass characteristics of finishing pigs. A total of 1,980 pigs divided into 2 groups [group 1: 1,008 pigs, TR4 × (Fast Large White × PIC L02) and group 2: 972 pigs, PIC 337 × 1,050], initially 33.3 kg, were used in a 103- or 114-d growth trial in groups 1 and 2, respectively. Treatments were arranged in a 2 × 3 factorial with 2 sources of added Zn, Zn hydroxychloride (ZnHyd; IntelliBond Z, Micronutrients, Indianapolis, IN) or Zn sulfate (ZnSO4), and 3 levels of added Zn (50, 100, or 150 mg/kg). Diets contained a vitamin-trace mineral premix without added Zn and provided 76 and 162 mg/kg Fe and Cu, respectively. All diets contained 750 FTU/kg phytase. There was a total of 14 replicates per treatment. Pens of pigs were weighed approximately every 2 wk to determine average daily gain (ADG), average daily feed intake, and gain-to-feed ratio. At the end of the experiment, pigs were transported to a packing plant to determine hot carcass weight (HCW), backfat depth, loin depth, and lean percentage. Overall, there was no evidence (P > 0.10) for interactive effects of added Zn source and level for growth performance and carcass characteristics. Pigs fed diets with increasing added Zn had a tendency (P = 0.093) for a quadratic response in ADG, with the greatest ADG observed at 100 mg/kg added Zn. There was a linear improvement (P = 0.010) in carcass yield and a quadratic response (P = 0.045) in HCW, with pigs fed 100 mg/kg added Zn having the highest HCW. Pigs fed diets with ZnHyd had improved (P = 0.017) carcass yield and a tendency (P = 0.058) for greater HCW compared with pigs fed ZnSO4. In summary, under the commercial conditions of the study and with diets containing 750 FTU/kg phytase, there were relatively small improvements in ADG of growing-finishing pigs fed added Zn beyond 50 mg/kg. Providing higher levels of added Zn improved carcass characteristics. Zinc source did not influence growth performance, but ZnHyd improved carcass characteristics compared with ZnSO4.

100 项与 TR-4 相关的药物交易

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