Crownvetch, Coronilla varia L., is relatively self‐incompatible. Plants selected to represent the full range of self‐fertility of a large sample of C. varia L. ‘Penngift’ were used in greenhouse experiments to locate the site or sites of incompatibility of self‐pollinations. Pollen germination and pollen tube growth in pistils after self‐ and cross‐pollinations were observed employing UV fluorescence microscopy.Pollen germination on the stigma and pollen tube penetration of the style occurred within the first 12 hours after self‐ and cross‐pollination. Pollen tubes reached ovaries within 24 hours for both types of pollination.In one experiment, the average number of germinated pollen grains on stigmas was significantly higher after crossing than after selling. However, this relationship between the two types of pollination was not consistent over the plants studied. For most plants, pollen germination on stigmas after cross‐pollination was about twice that after self‐pollination. This suggested that self‐incompatibility existed on the stigma. In the second experiment, using a different pollen source, the average number of germinated pollen grains on the stigma after crossing was not significantly different from that after selfing and the site of incompatibility seemed to be in the style.Pollen tube behavior in the ovary was the same for selfing and crossing in both experiments. For selfing, less ovules matured as seed than were penetrated by pollen tubes. Thus, both fertilization failure and post‐fertilization ovule abortion could have affected the amount of seed set after selling.Pollen germination and pollen tube behavior were the same in flowers from excised stems and stems growing on plants.

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A one‐man operated forage harvester was constructed by attaching a weighing basket from a hydraulic load cell to the self‐propelled Farmers Forage Research Plot Harvester. This new design allows the researcher to harvest a wide range of plot lengths and several different forage species with one machine. The weighing system was designed to reduce labor cost and harvesting errors accompanying alternative methods. The one‐man harvester was tested in the 1973 growing season on approximately 12,000 experimental plots and it demonstrated adequate precision, speed, and durability. We feel the initial cost and maintenance of this machine is completely justified and that it is a significant contribution to our forage program.