Top Photoselective Netting in Combination with Reduced Fertigation Results in Multi-Annual Yield Increase in Valencia Oranges (Citrus sinensis)

Fruit tree production is challenged by climate change, which is characterized by heat waves, warmer winters, increased storms, and recurrent droughts. The technology of top netting may provide a partial solution, as it alleviates climatic effects by microclimate manipulation. The tree physiological performance is improved under the nets, with an increased productivity and quality. The application of photoselective nets, which also alter the light spectrum, may result in additional horticultural improvements. We present the results of a 5-year experimental study on Valencia oranges, examining three nets: red, pearl, and transparent. Each net was tested at three fertigation conditions: a field standard (100%, I100) and two reduced fertigation regimes, which were 80% (I80) and 60% (I60) of the standard. The average multi-annual yield under the red and pearl nets with I100 and I80 and transparent net with I100 was significantly higher than that of the control trees. While the multi-annual yield increase under the red net I80 was due to the increase in the fruit number, in other treatments, the effect was mostly due to induction in the individual fruit weight. The data presented here show that an increased productivity of orange trees grown under photoselective nets, particularly the red net, with its specific spectral properties, was achieved with a considerable water-saving effect.

Mengurangi keterbukaan hutan melalui teknik pemananenan kayu yang tepat di hutan alam

Kegiatan pemanenan kayu memberikan kontribusi yang sangat besar terhadap produksi kayu. Pohon produksi yang berada di dalam hutan tidak dapat dimanfaatkan jika tidak ditebang dan tidak dikeluarkan dari dalam hutan. Metode penelitian ini adalah membuat 6 plot contoh pengamatan (PCP) masing-masing 3 PCP untuk teknik perbaikan (TP) dan 3 PCP untuk teknik konvensional (TK) pada satu petak tebang, melakukan penebangan pohon dan penyaradan dengan TP dan TK, melakukan pengamatan dan pengukuran produktivitas pemanenan kayu dan luas areal hutan yang terbuka akibat penebangan dan penyaradan serta menganalisis pengaruh kedua teknik terhadap produktivitas areal hutan terbuka dengan uji t. Tujuan penelitian adalah untuk mengetahui pengaruh dua teknik pemanenan kayu terhadap produktivitas dan areal hutan terbuka. Hasil penelitian menunjukkan bahwa : 1) Rata-rata produktivitas penebangan dengan TK dan TP masing-masing adalah 10,60 m3/jam dan 13,95 m3/jam 2) Rata-rata produktivitas penyaradan dengan TK dan TP masing-masing adalah 7,25 m3/jam dan 9,60 m3/jam; 3) Rata-rata areal hutan terbuka akibat penebangan dengan TK dan TP masing-masing adalah 15,67% dan 7,43% ; 4) Rata-rata areal hutan terbuka akibat penyaradan dengan TK dan TP masing-masing adalah 10,50% dan 6,68%. Menerapkan teknik perbaikan dapat mengurangi terjadinya keterbukaan hutan pada penebangan dan penyaradan masing-masing sebesar 8,24% dan 3,82%.ABSTRACTTimber harvesting provides a very large contribution to timber production. Tree production that is in the forest can't be used if they are not felling and removed from the forest. This research method is to make 6 sample observation plot (SOP) each 3 SOP for improving technique (IT) and 3 SOP for conventional technique (CT) on one logging compartment, do felling and skidding by IT and CT, make observations, and measuring the productivity of timber harvesting and the area of open forest due to felling and skidding and analyzing the effect of the two techniques on the productivity of the open forest area with t-test. The research objective was to determine the effect of two timber harvesting techniques on productivity and open forest areas. The results showed that the average productivity of felling by CT and IT was 10.60 m3/hour and 13.95 m3/hour respectively. The average productivity of skidding by CT and IT was 7.25 m3/hour and 9.60 m3/hour respectively. The average open forest area due to felling by CT and IT was 15.6% and 7.43% respectively. The average open forest area due to skidding by CT and IT was 10.50% and 6.68% respectively. Applying improve technique reduced the open forest area through felling and skidding by 8.24% and 3.82% respectively.

Carbon Footprint of Landscape Tree Production in Korea

Landscape trees sequester carbon during their growth processes, but they emit carbon through production in nurseries, which may offset carbon uptake. This study quantified the carbon footprint of landscape tree production. After determining the scope of life cycle for landscape tree production, the energy and material used to produce trees of a target size were analyzed by conducting a field survey of 35 nurseries. This energy consumption and input material were converted to an estimate of carbon emitted using data on carbon emission coefficients. The net carbon uptake was 4.6, 12.2, and 24.3 kg/tree for trees with a DBH of 7, 10, and 13 cm, respectively. Thus, even though carbon is emitted during the production process, landscape trees can act as a source of carbon uptake in cities that have high energy consumption levels. This study broke new ground for quantifying the carbon footprint of landscape tree production by overcoming limitations of the past studies that only considered carbon uptake due to absence of data on energy consumption and difficulty of field survey. These study results are expected to provide information on the carbon footprint of landscape trees and to be useful in determining optimal greenhouse gas emissions reduction goal through urban greenspaces.

Common Questions When Using Soil Moisture Sensors for Citrus and Other Fruit Trees

This guide is for Extension personnel who may encounter questions from growers about the functioning and accuracy of soil moisture sensors (SMSs) for fruit tree production. The 4-page publication focuses on two types of handheld sensors currently used in Florida for irrigation management of citrus and other trees: the transmission line oscillator (TLO) and time-domain transmissometer (TDT). Written by Eric Herrera, Sandra M. Guzmán, and Eduart Murcia, and published by the UF/IFAS Department of Agricultural and Biological Engineering, February 2021.

Characterization of Diaporthe spp. associated with spruce decline on Colorado blue spruce in Michigan

Since 2006 there has been a decline in Colorado blue spruce (CBS; Picea pungens) planted as landscape trees and for Christmas tree production throughout the Lower Peninsula of Michigan, United States. This decline is characterized by a slow loss of needles in the lower portion of the tree starting at branch tips, followed by entire branch dieback which gradually progresses upwards over several years. This dieback has been linked to shallow branch cankers visible in the phloem when the bark layer is removed. Isolates in the fungal genus Diaporthe have been consistently isolated from lesion margins on symptomatic branches. Prior to the initial reports of declining CBS in landscape and Christmas trees, Diaporthe was only known as a nursery disease of CBS. To determine the species of Diaporthe linked to the decline of CBS in Michigan, seven gene regions were sequenced from a collection of Diaporthe isolates collected in 2011-2018 from CBS and other coniferous hosts. Subsequent phylogenetic analyses indicated that Diaporthe eres and a novel Diaporthe clade were present on symptomatic CBS in Michigan. The new species Diaporthe brevicancria nov. is described, and Koch’s postulates were confirmed for D. brevicancria nov. and D. eres. Diaporthe brevicancria nov. produced the largest cankers in greenhouse pathogenicity trials and dual inoculations of D. brevicancria nov. and D. eres produced intermediate cankers.

Suitability Analysis for Moringa Oleifera Tree Production in Ethiopia - A Spatial Modelling Approach

Land suitability analysis is a basic premise for allocating specific land for specific purpose. The objective of this study was to predict the suitable sites for cultivating Moringa oleifera tree in Ethiopia using Spatial Analytic Hierarchy Process. Findings of this study will have paramount significance in supporting decision making in the agroforestry development sector. This study employs Spatial Analytic Hierarchy Process and Geographic Information System to generate valuable information in land allocation for moringa oleifera tree production. Climate, topography, soil type and land use parameters were evaluated for suitability analysis. The results of the study revealed that most of the central part of the country are categorized as moderately suitable for the production of moringa oleifera tree. Areas classified as highly suitable are distributed along the borders of southern and western part of the country. However, some of the central part was classified as not suitable for Moringa oleifera tree production. This paper tried to investigate analysis of spatial data to predict suitable site for moringa tree production at national level. At national level, highly suitable, moderately suitable, and not suitable class covers an area of 308,508.2, 1,628,930.8 and 59891.3 Square Kilometer respectively.