Foliar sprays of increasing concentrations (0, 75, 150, 300, 600, and 1200 mg·liter-1) of paclobutrazol were applied to `Cardinal' strawberry plants (Fragaria × ananassa Duch.) 35 days after transplanting. The plants were established in August in cultivated plots for measurement of paclobutrazol effects on first year growth or in a double-row hill system on black polyethylene-covered raised beds for 2nd year measurements. Increasing the paclobutrazol concentration reduced the number of runners, decreased runner length, and limited biomass partitioned into daughter plants. By the end of the first growing season, paclobutrazol had increased lateral crown development but reduced leaf area per treated plant. Root growth was reduced by concentrations >600 mg·liter-1. Treatment with 75 to 300 mg·liter-1 increased total plant dry weight by 33% to 46%. The following spring, plant growth was decreased by ≥ 300 mg·liter-1. Yield was increased by all treatments, except 1200 mg·liter-1. Leaf net photosynthesis increased within 12 days after treatment with paclobutrazol and was higher than in the controls the next summer. Leaf stomata1 conductance also increased the first year and was significantly higher the 2nd year after treatment. The optimum concentration of paclobutrazol for strawberries appears to be between 150 and 300 mg·liter-1.
`Embryonic axes-derived `Burpless Hybrid' cucumber (Cucumis sativus L.) plantlets germinated on Murashige and Skoog (MS) medium supplemented with 16 combinations of BAP and NAA and seedlings derived from whole seeds cultured on semi-solid agar were inoculated in vitro with two isolates (WFU3 and WFM13) of Pythium aphanidermatum. All axes-derived plantlets and whole seedlings inoculated with WFM13 isolates were susceptible to blight and died 2 days after inoculation. Similarly, all seedlings inoculated with WFU3 isolates were killed within 2 days after inoculation; however, the rate of development and severity of blight varied among the axes-derived plantlets. Blight on axes-derived plantlets, regenerated on MS medium supplemented with 2 mg BAP/liter and 0.2 mg NAA/liter, was significantly less than on regenerants cultured on all other amended MS media. On some media, callus developed on crowns and/or primary roots. The presence of callus influenced resistance to Pythium. In a second experiment, axes-derived cucumber regenerants from five genotypes, cultured on MS medium supplemented with 2 mg BAP/liter and 0.2 mg N&A/liter, were compared for their resistance to P. aphanidermatum isolate WFU3. Resistance was significantly greater for `Burpless Hybrid' and `Sweetslice' than for three other genotypes. Chemical names used: 6-benzylaminopurine (BAP); α -naphthaleneacetic acid (NAA).
mother and daughter plant and their heights were measured from crown to tip and their flower numbers were counted. The number of crowns was also counted on each mother plant and the three daughter plants as well as the total number of plants within the
, 2004 ; van Loon et al., 1998 ). Agrobacterium tumefaciens , a soil-borne bacterium, causes formation of crown galls in many plant species. During infection, a specific segment of the tumor-inducing plasmid, the transfer DNA (T-DNA), is transferred from
hill plastic mulch production (N. Peres, invited speaker, Southeastern Strawberry Expo, Nov. 9, 2006, personal communication). However, ‘Strawberry Festival’ has resistance neither to Colletotrichum crown rot caused by Colletotrichum gloeosporioides
Pollarded `Wichita' pecan [Carya illinoensis (Wang) K. Koch] trees received 2 g uniconazol (UCZ) per tree using four application methods (trunk band, canopy soil injection, crown soil injection, and crown drench). All application methods increased trunk diameter but reduced shoot length, number of lateral shoots per terminal, nodes per terminal, internode length, and leaflets per compound leaf. Only the crown drench reduced leaf area. Area and dry weight per leaflet, and leaflet chlorophyll concentration were not affected by UCZ application. Effectiveness in growth reduction, as assessed by shoot elongation, was crown soil drench > crown soil injection > canopy soil injection > trunk band > control. All application methods increased viviparity. However, total yield per tree, nut size, and percentage of kernel were not affected. Chemical name used: (E)-1-(p-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-1-penten-3-ol (uniconazol).
`Earliglow' strawberry (Fragaria × ananassa Duch.) plants were frozen to -5C to examine the distribution of ice in the crowns. Anatomical studies were also performed to characterize tissue growth in a greenhouse at 4, 8, and 16 weeks after freezing to -5C. Ice masses observed in fresh crown tissue corresponded to the presence of extracellular tissue voids in specimens fixed for scanning electron microscopy (SEM). Voids were present near the peduncle and adjacent to the vascular system in crown tissue. After plants were grown in the greenhouse, cell division and enlargement were observed near the voids in crowns subjected to -5C. By 15 weeks after freezing, a few small extracellular voids remained in the crowns.
minimally disturbed relative to production practices for a crop like blueberry where a tilled, mulch-incorporated and mulch-covered raised bed may be prepared. Thus, the blueberry plant’s crown and root system is established in three strata: mulch, mulch
storage tissues such as the crown and woody stems and in the fall from senescing leaves ( Mohadjer et al., 2001 ; Rempel et al., 2004 ; Strik et al., 2004 ) and externally from decomposition of plant tissues such as senesced leaves and roots and pruned
). Spring green-up was visually rated at Becker (24 Apr. 2009) and at St. Paul (25 Apr. 2009) using a 1–9 scale (9 = most green). Lateral spread [diameter (mm) at 4 cm above the soil] was measured at the widest expanse of the crown in one direction as well